Who first understood how eyes work?

occuity.com

2 pointsandsoitis3 comments

It's also worth mentioning Ibn al Haytham, who wrote the seven-volume Book of Optics in 1011 - 1021, and covered topics including how the eye handles reflected light. Also observed the effect of image inversion when developing the camera obscura.

There are many other scientists over the ages (whom we know a LOT about) that contributed to our understanding of eyes and optics. I don't think there are enough words in that article to really teach anything meaningful. The history is genuinely interesting, why write so little (even if it's just SEO)?

I want to know how they understand how cats and dogs see. They say certain colors, but how do they know for sure?

The eye has "rods" and "cones". Rods see in B&W (grayscale), and "cones" see in color. We have three types of "cones". Each see only one color: blue, green, red (it's actually more complicated, but they are defectively three types) When the green and red cones activate, your brain interpret yellow. And the other colors are also combinations. Take a look at https://en.wikipedia.org/wiki/Cone_cell

Dogs have "rods" and only two types of "cones": blue and yellow https://en.wikipedia.org/wiki/Dog#Senses They also interpret combinations, like us, but have less info to combine.

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